A Precise Optical to Infrared Transmission Spectrum for the Inflated Hot Jupiter WASP-52b

Transcription

1 A Precise Optical to Infrared Transmission Spectrum for the Inflated Hot Jupiter WASP-52b Munazza K. Alam Harvard University Exoplanets II July 5, 2018 Image Credit: NASA/ESA

2 HST/PanCET (Panchromatic Comparative Exoplanetology Treasury) - awarded 498 orbits on HST to observe 20 giant exoplanet atmospheres in the UVOIR GO 14767

3 The HST/PanCET team (Panchromatic Comparative Exoplanetology Treasury) - PIs: David Sing & Mercedes Lopez-Morales - CO-Is: Gilda Ballester (UoA, US) Joanna Barstow (UCL, UK) Lotfi Ben Jaffel (UCL, UK) Vincent Bourrier (Geneva) Lars Buchhave (Denmark) Offer Cohen (SAO, US) Drake Deming (Maryland, US) David Ehrenreich (Geneva) Tom Evans (Exeter, UK) Antonio Garcia Muñoz (TUB, Germany) Greg Henry (TSU, US) Tiffany Kataria (JPL, US) Heather Knutson (Caltech, US) Panayotis Lavvas (URCA, France) Alain Lecavelier des Etangs (IAP, France) Nikole Lewis (STScI, US) Avi Mandell (NASA Goddard, US) Mark Marley (NASA Ames, US) Nikolay Nikolov (Exeter, UK) Jorge Sanz-Forcada (CSIC, Spain) Hannah Wakeford (STScI, US) Other team members: Munazza Alam (CfA, US) Jayesh Goyal (Exeter, UK) James Kirk (CfA, US) Leonardo dos Santos (Geneva) (and others!) GO 14767

4 HST/PanCET GJ 3470b GJ 436b HAT-P-11b HAT-P-26b HAT-P-32b HAT-P-41b HD b HD 97658b KELT-7b WASP-6b WASP-29b WASP-52b WASP-62b WASP-69b WASP-74b WASP-76b WASP-79b WASP-80b WASP-101b WASP-121b Range of Parameters Planet Mass = 8 Mearth - 3 Mjup Radius = 2.0 Rearth Rjup Teff = K Orbital separation = AU Stellar irradiation level = Earth s irradiation Star V = Teff = K [Fe/H] = to dex GO 14767

5 HST/PanCET (Panchromatic Comparative Exoplanetology Treasury) - goal: produce the first large-scale, simultaneous UVOIR comparative study of exoplanets UV Optical Near-IR Mid-IR Transit Radius HST PanCET (PIs: Sing & López-Morales, starting Fall 2016 Wavelength (μm) GO 14767

6 WASP-52b M = 0.46 MJup R = 1.27 RJup Tp = 1315 K P = 1.75 days H = 700 km δ = Santerne et al. (2013)

7 WASP-52b may be cloudy clouds/hazes minor effect clouds/hazes major effect Stevenson et al. (2016)

8 Previous WASP-52b atmospheric studies claim discrepant conclusions Na I Rp/Rs K I Wavelength (nm) Chen et al. (2017)

9 Previous WASP-52b atmospheric studies claim discrepant conclusions Na I K I Rp/Rs Wavelength (Å) Louden et al. (2017)

10 HST/STIS transits of WASP-52b visit 52 (G430L) visit 53 (G430L) visit 54 (G750L)

11 Spitzer photometry GO (PI: Stevenson)

12 We correct for the effects of stellar activity

13 We correct for the effects of stellar activity

14 We correct for the effects of stellar activity

15 Sing et al. (2011) We correct for unocculted spots STIS Spitzer Wavelength (μm)

16 STIS+Spitzer transmission spectrum K I cloudy Na I K I Na I

17 We fit the transmission spectrum to the ATMO model grid (J. Goyal, poster #48) - open source suite of 3,920 forward models - scaled to WASP-52 parameters Teff ( K) metallicity ( x solar) C/O ( ) αhaze (1-1100) αcloud (0-1) Goyal et al. (2017)

18 STIS+Spitzer transmission spectrum K I cloudy Na I K I Na I

19 Comparing to HAT-P-1b WASP-52 HAT-P-1 Mass (MJ) ± ± Radius (RJ) ± ± Density (cgs) ± ± log(g ) (cgs) 4.58 ± ± 0.01 I (erg/cm 2 s) (6.5±0.4) x 10 8 (7.0±0.4) x 10 8 exoplanets.org

20 Comparing WASP-52b & HAT-P-1b in the optical Rp/Rs + constant Na I K I Wavelength (μm)

21 Fitting forward models for HAT-P-1b Na I

22 Comparing WASP-52b & HAT-P-1b in the near-infrared H2O CH4 JWST CH4 H2O STIS Spitzer

23 WASP-52b: spots in the near-ir (G. Bruno, poster #111) G. Bruno, M. K. Alam et al. (in press)

24 Conclusions - We present a μm STIS+Spitzer transmission spectrum for WASP-52b - We find that WASP-52b is cloudy with a 2.3σ detection of Na I, but no evidence of K I - WASP-52b & HAT-P-1b have similar system and atmospheric properties in the optical (but differ in the near-infrared)

25 Future Work - We aim to combine the STIS/Spitzer transmission spectrum with WFC3 observations - We retrieve the planet s atmospheric properties to constrain its chemical composition and estimate alkali abundances (G. Bruno, poster #111)